Centrifugal separator



Nov. 8, 1938. H. W. FAwcl-:TT

CENTRIFUGAL SEPARATOR Filed Oct. 8, 1937 l W l W Patented Nov. 8, 1938 PATENT OFFICE CENTRIFUGAL SEPARATOR Harold William Fawcett, Harrogate, England Application October 8, 1937, Serial No. 168,057

In Great Britain October 13, 1936 2 Claims.

'I'his invention relates to centrifugal separators of the kind having a bowl provided with peripheral discharge apertures the opening and closing of which is controlled by an hydraulically actu- 5 ated sleeve, ring, cylinder or the like surrounding the bowl and movable axially thereto. Centrifugal separators of this kind have been described for example in the specication of my United States Patent No 2,023,762. l

In the practical operation of centrifugal sepa rators of the foregoing kind, it has been found that the sleeve or the like tends to crossbind and stick as it moves along the bowl axis.

One object of the present invention is to prevent such cross-binding and sticking of the sleeve, ring, cylinder or the like surroundingy and movable axially of the bowl.

Another object of the invention is to provide a centrifugal separator in which the sleeve, ring, cylinder or the like surrounding the bowl or a member interposed between said sleeve or the like and the bowl is caused to execute a rotary movement on movement of the sleeve or the like axially of the bowl, for the purpose of preventing cross binding of said sleeve or the like.

Still a further object ofthe invention is to provide a centrifugal separator in which the bowl and the surrounding sleeve, ring, cylinder or the like interengage. 1

Further objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing, in which:-

Fig. 1 is a vertical section through one embodiment;

Fig. 2 is a detail of Fig. 1 in vertical section on an enlarged scale;

Fig. 3 is a plan of Fig. 2; and

Fig. 4 shows a detail of a modiiied embodiment.

In said drawing like parts are denoted by like characters of reference.

In the embodiment shown in Fig. 1, the reference numeral I denotes the bowl of the centrifugal separator which is provided with a plurality of peripheral discharge apertures 2 formed in members 3 screwed into the bowl. Said bowl`| is mounted on a spindle 4 for rotation. Surrounding said bowl I is a sleeve member 5` having apertures 6 arranged so as to register with the discharge apertures 2 on movement of the sleeve 5 axially of the bowl I. Said sleeve 5 is provided interiorly with an annular extension 1 which together with the part 8 of the outer wall of the bowl I and a ring 9 secured to the sleeve 5 by a lock ring I defines an annular cylinder space I which is movable axially of the bowl I and relatively to a stationary annular piston II secured by a lock ring I2 to the bowl I. Liquid is supplied to the cylinder space I5 alternately above and below the piston II through inlets I3 and I4 respectively Draining apertures I6 and I1 are also provided for draining liquid from the cylinder spaces above and below the piston II respectively on completion of the stroke of the cylinder in either direction.

In accordance with the present invention provision is made for preventing cross-binding of the sleeve 5 and the cylinder parts.

This can be eiected by providing the outer side of the bowl I and the inner side of the sleeve 5 with interengaging screw threads 20, of coarse pitch preferably about 45. By this means any tendency of one side of the sleeve 5 to move independently of the opposite side is prevented.

The bowl I and the cylinder member 1 are also provided with interengaging screw threads 22, 23. This form of construction has the advantage that the screw threads 22, 23 are shielded from discharging sludge and operate in a clean liquid such as water or oil.

In the foregoing embodiment the sleeve 5 executes a twisting movement relatively to the bowl I.

In order to obviate such a twisting movement, the sleeve 5 can be guided by any suitable means to execute a purely axial movement, having no rotary component.

To this end, as shown in Fig. 4, a ring 30 is interposed between the piston II and the part Ia of the bowl I. Said ring 30 is provided on its outer side with oblique teeth 3I which engage in corresponding teeth 32 formed in a replaceable ring 33 secured to the bottom projection 1 of the sleeve 5 by screws 34. The inner side of the ring 30 is not provided with teeth but is smooth so that said ring is free to rotate in a plane perpendicular to the bowl axis.

This embodiment operates as followsz On axial movement of the part 'I relatively to the bowl I, the oblique teeth 32 thereon, engage the corresponding teeth 3I on the ring 3B, whereby said ring is rotated. Since the rotation of the ring is the same throughout its circumference and it engages throughout its circumference with the member 33, any tendency for one side of 50 said member 'I to move axially in advance of the opposite side and thus of the sleeve 5 to crossbind, is effectively prevented.

1. A centrifugal separator comprising a bowl 65 lar member closely surrounding said bowl and reciprocable axially thereof, said annular member having apertures registering with said peripheral discharge apertures and serving to open and close said latter on reciprocation of said annular member, an annular shoulder on said bowl, a ring seated on said shoulder, and interengaging screw threads of coarse pitch on the outside of said ring and on the inside of the said annular member.

HAROLD WILLIAM FAWCETT. 

